T-shaped external chill



1966 A. P. STEINHAUSER T-SHAPED EXTERNAL CHILL Filed May 8, 1964 'centerof the mass.

United States Patent 3,287,772 T-SHAPED EXTERNAL CHILL Aloysius P.Steinhauser, Granite City, 11]., assignor to Amsted IndustriesIncorporated, Chicago, 111., a corporation of New Jersey Filed May 8,1964, Ser. No. 365,999

Claims. (Cl. 22-174) This invention relates to casting molten metal insand molds and, more particularly, to an external chill for controllingthe rate of cooling and shrinkage of a casting so as to obtain uniformsolidification thereof.

When molten metal is poured in a mold cavity, the periphery of the massof metal solidifies before the central part to form a rigid outer shell.The molten metal within the shell then cools, and hence solidifies,inwardly from the shell, tending to cause shrinkage away from the In thecase of castings which are formed with isolated sections that areheavier than adjoining parts, e.g., those including crosses, angles, TS,and Ys, cracks and voids are frequently formed because by the time themetal at the center of the mass reaches solidification temperature,there is insufficient metal to fill the space defined by the alreadysolidified shell.

Attempts to overcome the formation of these defects in castings includethe utilization of so-called chills. The chills, which may be of eitherthe external or internal types, promote directional solidification andreduce the elfect of severe temperature gradients caused by sharpchanges in metal sections of the castings. In general, internal chillsare more effective than external chills but suffer from the disadvantagethat extreme care must be taken in locating them. External chills, whichare fabricated of a metal having a high heat capacity and conductivity,are positioned so that they form a flush surface with the wall of thesand mold or core. When molten metal is cast, the met-a1 that contactsthe chill plate cools at a different rate than the metal that contactsthe sand so as to produce the desired surface hardening and otherdirectional heat flow required as the casting sets up.

While the utilization of external chills reduces the number of castingswhich are formed with defects, an undesirable high number of castingsare still formed with cracks and/or voids, as at intersecting ribs,walls, etc. As for example, a light pressed steel chill is usuallyeffective in eliminating cracks, but, however, does not in all caseseliminate voids within the casting. In contradistinction, when a solidforged or cast chill is used, many castings crack at the edge of thechill due to the severity of the effect of the chills mass.

This invention is based on external chills which are comprised of anelongated plate section from which a longitudinal cooling fin extends sothat the chills have somewhat of a T-shaped cross-section. The provisionof the cooling fin changes the effect of the chill plate so that thechills of this invention are more elfective than conventional chills ineliminating cracks and voids in castings. These chills are used in coresand molds, and can be easily produced from rolled T bars.

It is, therefore, a primary object of this invention to provide anapparatus for obtaining uniformsolidification of castings.

Another object of this invention is to provide an external ohill whichis substantially T-shaped in crosssection.

Still another object of this invention is to provide an external chillincluding a longitudinal cooling fin extending therefrom.

These and further objects of this invention will become apparent or bedescribed as the description thereof herein proceeds and reference ismade to the accompanying drawings in which:

3,287,772 Patented Nov. 29, 1966 FIGURE 1 is a rear elevation showingthe preferred embodiment of the cooling fin;

FIGURE 2 is an end view of the chill illustrated in FIGURE 1; and

FIGURES 3 and 4 are sectional views through the planes 33 and 4-4,respectively, of FIGURE 1.

The chills of this invention are best described by reference to theaccompanying drawings wherein the reference numeral 10 designates thechill .plate portion of substantially uniform thickness having convexface 12 which is curved transversely with respect to the length thereofso as to precisely conform to the radius of curvature of the mold cavitywhere the chill is to be used. Extending from between the longitudinaledges of face 14, opposite face 12, is elongated cooling fin 16 whichwill be embedded in the sand core or mold. Fin 16 preferably extends ina substantially radial direction from midway between the longitudinaledges of face 14. Chill plate 10 and cooling fin 16 are each fabricatedof a metal having a high heat capacity and conductivity, and theseportions are usually fabricated of the same met-a1.

In the preferred embodiment of cooling fin 16, it is formed with asubstantially straight longitudinal edge portion 'adjOiHing chill plate10 and a sinuous longitudinal edge portion remote from chill plate 10,as illustrated, so that it can be securely anchored in the sand. It willbe apparent that the extent of the sinuousness of the edge portion offin 16 remote from plate 10 will depend upon the size of the chill, butcooling fin 16 will be off-set from the radius of plate 10 about 10degrees at the maximum areas of deflect-ion.

Although the chill is illustrated as having a convex outer face (face 12of FIGURE 1), it will be apparent that the outer face can be otherwiseshaped i.e., either concave or flat, so as to conform with a convex orflat surface of a mold cavity.

I claim:

1. An external chill which comprises an elongated metallic body ofsubstantially uniform thickness presenting a convex outer face which iscurved transversely with respect to the length of said body and anelongated metallic fin extending in a substantially radial directionfrom the center of the face of said body opposite said outer face, saidfin having a substantially straight longitudinal edge portion adjacentto said body and a sinuous longitudinal edge portion remote from saidbody.

2. An external chill which comprises an elongated metallic body ofsubstantially uniform thickness presenting a convex outer face which iscurved transversely with respect to the length of said body and anelongated metallic fin extending in a substantially radial directionfrom the center of the face of said body opposite said outer face, saidfin being coextensive with said body and having a straight longitudinaledge portion adjacent to said body and a sinuous longitudinal edgeportion remote from said body, said fin being further characterized asbeing off-set about 10 degrees from the radius of said body at themaximum deflection of said sinuous longitudinal edge portion.

3. In combination with a mold having a cavity for receiving moltenmetal, a chill fabricated of metal which comprises an elongated bodypresenting an outer face which is flush with a wall of said cavity andcurved transversely with respect to the length of said body and anelongated fin extending from between the longitudinal edges of the faceof said body opposite said outer face, said fin having a substantiallystraight longitudinal edge portion adjacent to said body and a sinuouslongitudinal edge portion remote from said body.

4. In combination with a mold having a cavity for receiving moltenmetal, a chill fabricated of metal which comprises an elongated body ofsubstantially uniform thickness presenting a convex outer face which isflush with a wall of said cavity and curved transversely with respect tothe length of said body and an elongated fin extending in a radialdirection from the center of the face of said body opposite said outerface, said fin having a substantially straight longitudinal edge portionadjacent to said body and a sinuous longitudinal edge portion remotefrom said body.

5. In combination with a mold having a cavity for receiving moltenmetal, a chill fabricated of metal which comprises an elongated bodypresenting an outer face having a substantially straight longitudinaledge portion adjacent to said body and a sinuous longitudinal edgeportion remote from said body.

References Cited by the Examiner UNITED STATES PATENTS I. SPENCEROVERHOLSER, Primary Examiner.

V. K. RISING, Assistant Examiner.

1. AN EXTERNAL CHILL WHICH COMPRISES AN ELONGATED METALLIC BODY OFSUBSTANTIALLY UNIFORM THICKNESS PRESENTING A CONVEX OUTER FACE WHICH ISCURVED TRANSVERSELY WITH RESPECT TO THE LENGTH OF SAID BODY AND ANELONGATED METALLIC FIN EXTENDING IN A SUBSTANTIALLY RADIAL DIRECTIONFROM THE CENTER OF THE FACE OF SAID BODY OPPOSITE SAID OUTER